About Sizeaholic

Honest numbers about size and fit, built by people who care more about the math than the clicks.

Sizeaholic is built by the team behind Calcaholic.com, a site with more than a hundred calculators for everything from mortgages to GPAs. We spend our days making sure numbers are right. This site gives one topic that treatment full time: sizing.

Why this site exists

Sizing on the internet is a mess. A US shoe size means something different in the UK and something different again in the EU. Clothing sizes drift year by year as brands flatter their customers. Conversion charts disagree with each other, and much of what ranks in search results is marketing copy designed to sell you something rather than to answer your question.

So we build calculators on published standards and peer-reviewed research instead. Every tool on this site documents its formula, cites its sources, and shows a worked example, so you can check our work rather than take our word for it.

The same rules as Calcaholic

• Nothing you type is stored. Every calculation runs in your browser, on your device. Your measurements never touch a server. Our privacy policy spells it out.
• Every page shows its formula. You can see exactly how a result was computed and verify it yourself.
• Honest ranges, stated assumptions. We tell you where the data comes from and what it can and cannot say.

The tools

We launched in July 2026 and the site now covers six departments:

• Shoes: converters for US, UK, and EU sizes, men's and women's scales, kids sizes, and brand charts like our Converse size chart.
• Clothing & Accessories: ring size, hat size, bra size, pant size, and twelve more.
• Sports & Outdoors: bike frame size from your inseam, ski and snowboard length, skateboard deck width, and gear that is sized by something other than the obvious measurement.
• Home & Auto: bed and mattress dimensions with a room fit check, TV size and viewing distance, tire sizes, and paper sizes.
• Pets: dog collar size from the neck, harness size from the chest, and crate size from length and height, because none of the three can be read off the others.
• Body & Intimacy: clinical, research-backed tools for condom sizing and size statistics, built on clinician-measured studies rather than internet surveys. The privacy rules above matter most here, and they are the same on every page.

Who writes this

Sizeaholic is written and maintained by the Calcaholic team rather than by a single named author. We are not doctors, tailors, or fitters, and we do not claim to be. What we do claim is narrower and checkable: every calculator states the formula it uses, cites the standard or study behind it, and shows a worked example, so you can verify a result instead of trusting us for it.

Where a number comes from published research we name the study and link it, as on our average size chart. Where it comes from a standard we name the standard, such as ISO 8653 for ring sizing or ISO 4074 for condom widths. Where the published sources genuinely disagree, as they do for boxing glove weights, we say so and show the disagreement rather than picking one and presenting it as settled.

If there is a size or fit question you wish had an honest calculator, tell us. That is how most of our tools get built.